The effects of chronic cerebral insult and neuropsychiatric disorders were evaluated by a broad range of neuropsychological tests evaluating brain-behavior relations. Asymptomatic and symptomatic children with Gaucher's and Niemann-Pick disorders were examined with neuropsychological and psychoeducational procedures.preliminary data indicate that presymptomatic patients manifest selective cognitive deficits, more so with attention and memory tasks. One finding suggests that these children are selectively troubled by visuospatial and constructional deficits, with academic expression in the form of orthographic (spelling) disorders. Adolescents with obsessive-compulsive features exhibited a configuration of neuropsychological deficits which correlated with ventricular enlargement. Deficits were identified in spatial judgment and spatial learning. An imbalance in the inhibitory functions of frontal and limbic systems may propel obsessive-compulsive behavior.